You have to use NWC (click and hold the the Zap icon to set it up). If you are using external wallets, there is no good way to pay everyone in the background.
Discussion
Zapsplit with nwc isn't working. It fails on second wallet and gives up.
Hang on, spoke too soon. Zapsplit seems to be working... Just no notification...
Alright, I'll look into it! I think this zapsplit works great with open-source patch announcements like this!
tested and checked; it works!